In order to supply electricity to rail vehicles that are powered by electric motors, sliding contact devices, also referred to by the technical term “pantographs” and equipped with a sliding strip, are pressed as a wearing part against a drive power conductor (overhead wire) by a biasing force generated by the pantograph and form a sliding contact, thereby enabling electric current to be conducted while the vehicle is travelling.
In order to ensure that the sliding contacts between the sliding strip and the overhead wire are maintained as continuously as possible even during the dynamic travelling operation of such rail vehicles, it is known to be advantageous to keep the mass inertia forces of the pantograph, of which the mass of the sliding member is an essential component, as low as possible. At the same time, in order to enable the effective operation of vehicles powered with electric motors, it is necessary to ensure that the sliding strip is sufficiently capable of conducting electricity and that it has low electrical resistance. For this reason, impregnating the porous carbon with a metal has proven to be unsatisfactory, since the good electrical conductivity achieved thereby is associated with an undesirable increase in the mass of the sliding strip due to the metal component formed in the sliding strip by the impregnation.
Given this state of the prior art, it has therefore already been suggested in EP 1 491 385 A1 to implement measures that enable a low specific electrical resistance, that is to say good electrical conductivity in the sliding strip, while at the same time keeping its density as low as possible, which equates to a correspondingly low mass of the sliding strip.
As a solution to this problem, it is suggested in EP 1 491 385 A1 to manufacture sliding strips from a composite material that has a sandwich structure of carbon layers, between each of which are arranged metal meshes that extend in a plane transverse to the sliding direction of the sliding strip and in the biasing direction of the biasing force that is exerted on the sliding strip by the sliding contact device.
The manufacture of the known sliding strip has proved to be relatively complex because of its sandwich construction as described in the preceding, because individual carbon layers must be manufactured first, then the previously described sandwich construction must be created by arranging the metal meshes between the individual carbon layers, and only then can a composite body or carbon moulded body be produced that in its entirety forms the sliding strip.